Southern Baja California; also Cerralvo I and perhaps sporadically on San José I (Gulf of California). Recent vagrant to southern California (USA), where attempted to nest.
 
Population
Estimated population is 20,000 - 49,999 (2010).
Xantus's Hummingbird (Basilinna xantusii) [XC702506]
by Sue Riffe from San Antonio de la Sierra, Baja Sur, Mexico (call)
Xantus's Hummingbird (Basilinna xantusii) [XC352767]
by id from Sierra Las Pirras, Baja California Sur, Mexico (call)
Subspecies
Genus often merged into Hylocharis, though external morphology suggests closer relationship to Lampornis. Forms a superspecies with White-eared Hummingbird (Basilinna leucotis).